The goal of this research is to develop a unique respiratory gas analyzer for both oxygen and carbon dioxide, characterized by very fast response, high stability, and significant cost savings. It incorporates new approaches to sensing O2 and CO2 not previously demonstrated in gas analysis. In Phase I, the applicant organization demonstrated proof-of- concept by building a prototype whose specifications currently exceed those of some commercially available gas analyzers costing three times as much. The technology also provides many practical advantages, e.g., the weight of the combined O2/CO2 analyzer is less than 2.5 kg, while competitive gas analyzers weight over 28 kg. Projected cost is approximately $5,000. Proposed Phase II research will improve the design, including extending the capability to pediatric and neonatal applications, and incorporate the resulting gas analyzer into a complete metabolic analysis system. Both bench testing and validation with human subjects will take place. This research will lead to a new technology useful and cost effective for patient monitoring, exercise stress testing, metabolic analysis, and monitoring of controlled atmospheres such as hyperbaric chambers. There are also industrial applications, including greenhouse monitoring, food processing, and pollution control. The applicant's organization has a successful track record in developing and commercializing SBIR technology. PROPOSED COMMERCIAL APPLICATION: Commercial applications include health-related applications such as patient monitoring, metabolic measurement, exercise stress testing, and nutritional evaluation. Other industrial applications include greenhouse monitoring, food processing, and other environmental monitoring. The resultant O2/CO2 gas analyzer will be marketed as a stand alone product and incorporated into a metabolic analysis system.